How can I increase my chances?

I am a high school Junior in North Carolina at a large public school.

ACT: 35 composite (36 E, 35 S, 33 M, 34 R, 10 W)
GPA unweighted: 4.0
planning to take SAT subjects in Physics, Math II, and US History
AP: World (5), Stats (5), US (4-5 predicted), Physics (4-5 predicted), Language and Comp (4-5 predicted)
Senior Course load: AP Physics C, AP Spanish, AP Lit, AP Chem, AP Calc BC, AP Psych, Hon Orchestra
Rank: Top 10%
Awards: Various School character and merit awards, Carson Scholars Award, Science Olympiad awards, debate awards

Extracurricular (this is what I’m the most worried about): Co-founder of Asian Club; Science Olympiad, Speech and Debate, Orchestra, Service Learning Ambassador, NHS, Spanish Honor Society, Twelve Club, Youth group (President), Praise Team (leader), physical therapy for 2 hours a day minimum (physical disability)
Volunteer: Science Center volunteer (200 hours), Disability Advocacy group (96 hours), Hospital Volunteer (36)
Summer Activities: Governor’s School for science, volunteering

How are my chances for schools like USC, Johns Hopkins, NYU, Cornell, Brown? And how can I improve my stats and extracurricular activities?

bump

Your academics are great, but your EC’s seem really spread. Maybe you should start focusing on one type of volunteering on something related to your intended major. Regardless, you exceed the minimum for all those schools. You should be fine.

How could I improve my EC’s?

Eh, you probably get in NYU and USC regardless of improving ECs… though USC does really like ECs.

And the only way to significantly improve ECs is to find something and make it yours. Like to write? Start writing in massive amounts and get things you’ve written out there and read by many and published. Like math and science? Win a math and/or science competition at a high level.

Or try to intern or something of that variety… but in any case, find something and make it YOURS.